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Author Topic: 'CB' amplifier for HF  (Read 1180 times)

Offline Elf36

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'CB' amplifier for HF
« on: February 16, 2022, 1356 UTC »
How well would a CB type amplifier work on bands such as 15/20 meters? Talking about the standard Texas Star/RM Italy type. I'm wanting to buy a Xiegu G90 and it would be nice to be able to use it mobile here and there.
Yaesu FT-950, 135' OCF dipole @ 28', SignaLink interface, Vibroplex Square Racer paddle and a Grundig G3 when portable.

Offline M R I

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Re: 'CB' amplifier for HF
« Reply #1 on: February 16, 2022, 1640 UTC »
It can be done if you can get it to tune on lower bands. Otherwise modifications will be in order.
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Offline Stretchyman

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Re: 'CB' amplifier for HF
« Reply #2 on: February 16, 2022, 1918 UTC »
Depends on the model. If it's built for CB then it won't work anywhere else.

What are you trying to achieve?

Str.
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Offline Elf36

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Re: 'CB' amplifier for HF
« Reply #3 on: February 16, 2022, 1940 UTC »
I guess I would say I'd like to achieve a way of having more power on bands like 10,12,15 & 20M on a budget. It would be nice to have a bit of extra power while operating mobile, especially just having a Hamstick type antenna. I have heard that some of these type amplifiers are more linear than others. If my memory serves me correct, RM Italy amplifiers were being discussed specifically. I can't seem to find the forum online where I read that.
Yaesu FT-950, 135' OCF dipole @ 28', SignaLink interface, Vibroplex Square Racer paddle and a Grundig G3 when portable.

Offline ThaDood

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Re: 'CB' amplifier for HF? Maybe, with a MOD.
« Reply #4 on: February 16, 2022, 1952 UTC »
I have the latter Kris - Big Boomer amp, (The non-6M version.), and it will do 12M, 11M, and 10M, very nicely, but the filters won't go +/- past those bands. And, I've tried 15M. Nope... It's a HOT amp too, 1W IN = 230W OUT. Yeeeesh... So, I can use that on my RCI-2950 cranked down and the newer Xiegu G90 cranked down to 1W, and even the MOD'ed Cherokee AH-100 AM / SSB HT on 10M. But, too hot for my Icom and Kenwood rigs, without attenuation.
I was asked if I liked the 80's pop band The Go-Go's, and I answered that I listened to them, like many other Top 40 pop bands of the time, so Eh. However, I did mention that I did kind of feel sorry for them, since I thought that the band members couldn't have sex. I was then asked, "What do you mean?" My reply was, "Duh... They sing about it themselves, their lips are sealed!".

Offline Stretchyman

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Re: 'CB' amplifier for HF
« Reply #5 on: February 16, 2022, 1957 UTC »
Some are linears and broadband and some are narrow band (CB only). 2 completely different animals.
'It's better to give than receive' so why RX when you can TX!

         15W, 60W and 100W models available.

                   Buy one from me, NOW!


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Offline Elf36

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Re: 'CB' amplifier for HF
« Reply #6 on: February 16, 2022, 2007 UTC »
Yeah, maybe as propagation gets better I will still get one to use on 10/12 meters. Back in the late 90's I had a 250 watt amp in my truck. I was driving it with a HR2510 going to a trimmed 102'' whip. It was a great set-up. Thanks for the feedback.
Yaesu FT-950, 135' OCF dipole @ 28', SignaLink interface, Vibroplex Square Racer paddle and a Grundig G3 when portable.

Offline Stretchyman

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Re: 'CB' amplifier for HF
« Reply #7 on: February 16, 2022, 2040 UTC »
Yes we all remember CB in the 80s, best skip ever.

However it's just CB.

17m for me..

Str.
'It's better to give than receive' so why RX when you can TX!

         15W, 60W and 100W models available.

                   Buy one from me, NOW!


                                              ;)

Offline moof

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Re: 'CB' amplifier for HF
« Reply #8 on: February 16, 2022, 2059 UTC »
I couldn't tell you about Texas Star, but I have had zero problems with old linears on 10-40's meters with stuff like Pride, Grey, even a generic looking 100 watt HME box.  I believe the old ones generally worked 3-30 mhz.  Now I DID have problems with my only expensive purchase, the RM Italy about 10 years ago.  It was I believe a 150, fan or two on top, knob band selector on the left, billed as 1.8-30mhz.  Absolute P. O. S.  Tested on the bench with a Cobra stock CB.  Worked ok, but not real impressed with output.  Mobile I could not get it to work >90% of the time.  I tried everything 1-10 watt input, connections, 10m, 40m.  No reason why it decided to work once for a minute then not.  Other amps worked just fine.  Luckily got my $ back.
So gitcha an old cheaper one.  Only issues I have had with them is fuse getting sizzly from age and poor connection.  So chop off and add new wire with fuse.  I have also never had to replace a cap in any of the 4 I have which is amazing.  If you 'chaw' minutes+ straight at a time, put a fan on top.

Offline JustGreg

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Re: 'CB' amplifier for HF
« Reply #9 on: February 16, 2022, 2314 UTC »
I know Radio Oddity sells Xiegu equipment.  I did a quick check and found this amp for the G90.
https://www.radioddity.com/collections/mobile-radio-amplifier/products/xiegu-xpa125b
You may want to take a look at it.  It is 100 watts with a built in antenna tuner.

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Offline Elf36

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Re: 'CB' amplifier for HF
« Reply #10 on: February 17, 2022, 0008 UTC »
Yes. I came across that also. Seems a bit insane to pay $600.00 to make a $425.00 radio produce 100 watts. You could buy a brand new Yaesu FT-891 for another $39.00 or so and many other used rigs that put out 100 watts and likely have 6M as well. It's the same with the optional GSOC touch screen controller that cost $420.00. Thanks for the info though.
« Last Edit: February 17, 2022, 0012 UTC by Elf36 »
Yaesu FT-950, 135' OCF dipole @ 28', SignaLink interface, Vibroplex Square Racer paddle and a Grundig G3 when portable.

Offline RobRich

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Re: 'CB' amplifier for HF
« Reply #11 on: February 17, 2022, 0307 UTC »
Harmonics and IMD are the big issues. Most 11m amps do not even have low pass filtering for 11m, less long any other band. You might put a cheap 30MHz lowpass filter after the amp, keep the output far below spec, and get away with a CB amp on 10m.

HF is already populated with plenty of "all knobs to the right" radios splattering harmonics across wide swaths of spectrum. Please do not add to it.

My thoughts on mobile? Unless you want to run QRP, opt for an 100w radio. Next look at the real issue with mobile setups… antenna efficiency. I would rather spend money on a decent screwdriver antenna and effort on proper tuning and ground bonding than deal with a costly amateur mobile amp plus the usual amp-related power delivery issues. For most amateur purposes, dBs are dBs, regardless if you are obtaining them from antenna gain/efficiency or watts.



Not to be confused with its 11m product line, RM Italy does offer HF amateur radio amps with selectable band filters.
« Last Edit: February 17, 2022, 0315 UTC by RobRich »
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Offline Polar Bear

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Re: 'CB' amplifier for HF
« Reply #12 on: February 22, 2022, 2047 UTC »
AMATEUR RADIO EQUIPMENT MUST BE LINEAR, IT MUST BE BUILT IN SUCH A WAY AS TO CONFORM TO THE RULES AND REGULATIONS SET FORTH BY THE FCC.

Citizens band amplifiers tends to not conform to those rules..  Most are built on class c architecture.
Class C is ok if you are operating AM or CW, but is too wide for use for SSB phone.

No one says that an amplifier has to be expensive.  I bought several at auction for $65 each - 600 watt Ameritron and Dentron.

But, when you are a licensed amateur - you are held to a higher standard then the citizens band..

Part of this is in reference to - self training.  You don't need an amplifier.
What you do need is an Elmer.. Someone willing to invest time in you to teach you the fundamentals of physics and amateur radio - because obviously you aren't willing to invest that time in yourself.

If you would read - and there is many excellent articles online, they would teach you that your first and best investment should always be in a better antenna.

We all start out with some type of dipole, we then move on to beam antennas and then upgrade to stacked beam antennas.  Vertical antennas can be used if you have the proper take off angle.
Next to salt water is almost a must if you wish to operate DX.
A beam antenna gives you the advantage of appearing to have more power, without the investment of an amplifier, and it pays huge dividends when it comes to operating.

The second major investment is in good coax.  You always use the coax with the least amount of loss.
That Belden 9913 or LMR 400 is the best bang for the buck. Even better is if you can use as much hardline as possible.  Just look at the website of any major contest station and you will see miles of hardline and almost no RG8x.

Then there is the understanding that we don't talk in watts when it comes to RF, we talk in decibels.

The biggest bang for the buck is a 600 watt amplifier, because it has the most DB improvement over a 100 watt transceiver.  1000 watts or 1500 watts aren't that many more db over 600 watts.

Again, it all goes back to investing in low loss feed line and a good antenna vs the old G5RV and an amplifier some people calls a G5RV - nothing but a waste of time.  And the antenna tuner doesn't physically tune the antenna to resonance, it just tricks the transmitter into applying most of its power into the antenna tuner, when it is turned into heat - since anything not absorbed by the load is reflected back towards the source.

My only gripe is the people with the poor antenna situation, using an amplifier to sound like The Wizard of Oz, and then the only people they can hear is other people using an amplifier.
The amplifier doesn't improve the receive, only the transmit.
Even if you use a pre amplifier, when you amplify noise, all you get is a louder noise..

Offline Elf36

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Re: 'CB' amplifier for HF
« Reply #13 on: February 22, 2022, 2159 UTC »
This was a simple topic in regards to 'Mobile operation' with a simple hamstick type of antenna. 'Where having a bit of extra power would be quite useful. I do not own an amplifier. I have a simple setup at home, running 100 watts into a dipole and get by just fine. No one said 'Hey can you help me come up with a fake call sign or What's the best way to run 1200 watts from a class C linear into a tribander on 15/20 meters. Just a simple topic for discussion. In regards to coax, I do use LMR for VHF/UHF and happen to use RG-213 for my HF stuff. The only reason I went above something like RG8 was that I already had some 213 on hand. Running LMR400 HF would be a waste of money. I'm always up for good advice, but I don't need an elmer. I've been at this for quite a while. I just never messed around with amplifiers much. Your response could have been spread over 9 different topics.

'You don't need an amplifier'
'No one says that an amplifier has to be expensive.  I bought several at auction for $65 each - 600 watt Ameritron and Dentron'
'The biggest bang for the buck is a 600 watt amplifier'
« Last Edit: February 22, 2022, 2204 UTC by Elf36 »
Yaesu FT-950, 135' OCF dipole @ 28', SignaLink interface, Vibroplex Square Racer paddle and a Grundig G3 when portable.

Offline radiogaga

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Re: 'CB' amplifier for HF
« Reply #14 on: February 23, 2022, 0131 UTC »
How well would a CB type amplifier work on bands such as 15/20 meters? Talking about the standard Texas Star/RM Italy type. I'm wanting to buy a Xiegu G90 and it would be nice to be able to use it mobile here and there.

A Texas Star drops off fast on power outside 11 meters. As moof noted most the older models are 3-30mhz. I had good results with the the older Messenger brand units. Make sure to get an ab biased model if you plan to use ssb. My experience with the RM Italy is opposite of what is posted. I run the RM HLA 150 at CCS at 50% output without a hiccup as my driver amp.

rgg

 

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